I've realised a long time ago that all of programming essentially consists of two things: data, and procedures that operate on that data. Everything else is in

I've realised a long time ago that all of programming essentially consists of two things: data, and procedures that operate on that data. Everything else is in function in one or both of these two things. For example - functions and methods organise the procedures in smaller, more manageable (from human perspective) chunks, types formalise and limit the data to make them easier to transfer and organise, and classes (are supposed to) do both.